package xjnu.edu.file;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DownloadFileServlet extends HttpServlet {
	
	private static final long serialVersionUID = 1L;

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		request.setCharacterEncoding("utf-8");
		String filename = request.getParameter("filename");
		System.out.println(filename);
		response.setContentType(getServletContext().getMimeType(filename));
		response.setHeader("Content-Disposition", "attachment;filename="+filename);
		String fullFileName = getServletContext().getRealPath("/WEB-INF/upload/" + filename);
		
		InputStream in = new FileInputStream(fullFileName);  
        OutputStream out = response.getOutputStream();
        int b;  
        while((b=in.read())!= -1)  
        {  
            out.write(b);  
        }  
          
        in.close();  
        out.close();  
    }  

}
